A total of 28 Wimbledon staff have now been asked to stay at home after suffering flu-like symptoms, tournament organisers said.

Fears over a possible swine flu outbreak were raised two days ago after four ball boys and girls were asked to stay away.

Several more people have now been asked to stay away from the championships, including one member of staff working in the Wimbledon shop, one person from the broadcast centre, members of the catering staff and more ball boys and girls.

It has also been reported that three players are believed to have contracted the virus.

A Wimbledon spokeswoman said: “Twenty-eight Wimbledon personal have been asked to stay at home with flu-like symptoms.

“But of the initial ball kids who were affected, three are now back at Wimbledon and fine to work.

“Once they have been without symptoms for 24 hours they are allowed back to work – and the ball kids are obviously desperate to get back on court.”

Senior Wimbledon doctor Fenella Wrigley said the incidence of those affected reflected the broader situation in London.

She said the spread of the virus was being monitored but numbers had not increased more than expected.

According to the Mail newspaper, three players are believed to have caught the virus.

They are Slovakians Michal Mertinak and Filip Polasek who shared a hotel room for the tournament, and American Travis Parrott, Polasek’s doubles partner.